1. Field
The following description relates to a method and apparatus for controlling a signal transmission which controls whether to cooperatively transmit a signal using a data rate and a signal to noise ratio (SNR) between a base station and a signal receiving node.
2. Description of Related Art
In cellular communication environments, a user located in a cell edge experiences a case where a data rate is degraded due to co-channel interference (CCI) from adjacent base stations using identical frequency resources.
Accordingly, there has been research for network multiple-input multiple-output (MIMO) to enable multiple base stations to cooperatively transmit signals in order to remove CCI experienced by users and to improve a data rate.
In the case of a downlink for network MIMO, performance may vary depending on accuracy of feedback information since channel information between transmission/reception is required to be known to a base station.
Research for improving the performance of network MIMO is helpful for limited feedback environments in that it is difficult to perfectly feedback channel information to a base station in an actual communication system.
Factors such as inter-user interference (IUI) and CCI affect the performance of network MIMO in the limited feedback environment. In general, comparing the relative impact of the two factors on performance of a communication system, the IUI affects performance degradation of the communication system to a greater degree than the CCI in a cell edge, and the IUI causes performance degradation of the communication system in a center of a cell.
When multiple base stations transmit signals to users, the CCI may be removed, yet the IUI may be increased due to an error occurring between a quantized channel vector and an actual vector.
Therefore, a new technique capable of improving the performance of a communication system by cooperatively transmitting signals to users in consideration of impact of the CCI and the IUI is desired.